Spermiogenesis is a complex process of differentiation and morphologic alteration, in which sperm acrosome formation is an important stage. Acrosome is an essential component of the sperm head, which develops in four distinct phases: Golgi, cap, acro- somal, and maturation, each supported by precise and orderly regulation of various genes. The regulatory genes which act on Golgi ap- paratus include GOPC, Hrb, SPATA16, PICK1, and CK2α', those involved in the cap phase are Fads2, syntaxin 2, Kdm3a, and UBR7, and participating in acrosomal and maturation phases are KIFC1, Rnf19a, and DPY19L2. The abnormalities of these genes may affect male fertility by influencing the connection of the nuclear dense lamina and acroplaxome with the nuclear membrane and then the fusion and transportation of vesicles. This review focuses on the genes involved in different phases of acrosome formation.
Acrosome ; physiology ; Animals ; Golgi Apparatus ; Male ; Mice ; Sperm Head ; physiology ; Spermatids ; growth & development ; Spermatogenesis ; genetics ; Spermatozoa ; growth & development

In human reproduction, fertilization is the first step for successful pregnancy. From the perspective of sperm physiology, the progressive motility and capacitation, including hyperactivation and acrosome reaction, are the most important factors in the fertilization of oocytes. Numerous studies have demonstrated the roles of calcium ions, cyclic nucleotides, and bicarbonate in the acquisition of progressive motility and capacitation. Among these factors, calcium ion plays the most important role. Sperm possess several calcium channels, including voltage-gated calcium channel, cyclic nucleotide-gated calcium channel, transient receptor potential channel, and channels of the CatSper family The CatSper family is a newly-identified group of four sperm-specific cation channels. CatSper1 and CatSper2 proteins localize on the sperm tail and play a critical role in sperm motility and fertilization. In contrast, CatSper3 and CatSper4 proteinsare expressed only in the acrosomal region of sperm head, which implies that they may have a role in the acrosome reaction. Taken together, the CatSper family is the most important group of calcium channels for regulating sperm physiology and appear to be an attractive target for non-hormonal male contraceptives.
Acrosome Reaction ; Calcium ; Calcium Channels ; Contraceptive Agents, Male ; Fertilization ; Humans ; Ions ; Nucleotides, Cyclic ; Oocytes ; Physiology ; Pregnancy ; Reproduction ; Sperm Head ; Sperm Motility ; Sperm Tail ; Spermatozoa

OBJECTIVETo compare the criteria of sperm morphology evaluation in the fifth edition of WHO Laboratory Manual for the Examination and Processing of Human Semen and those in the fourth edition, and to know the changes in the criteria of sperm morphology evaluation in the new edition.

METHODSNine technicians from Zhejiang Human Sperm Bank evaluated the morphology of 1 000 spermatozoa in 96 sperm morphological pictures according to the criteria in the fourth and fifth editions of WHO Laboratory Manual, respectively.

RESULTSThe percentage of morphologically normal sperm by the criteria of the fifth edition was (26.50 +/- 5.06)%, significantly higher than (11.39 +/- 3.17)% by the fourth edition (P < 0.05), while the rates of sperm head and tail defects based on the former were (64.26 +/- 7.66)% and (10.92 +/- 2.03)%, significantly lower than (76.11 +/- 8.18)% and (39.89 +/- 3.85)% according to the latter (P < 0.05). There were no significant differences in the rates of sperm midpiece defects and excessive residual cytoplasm by the fifth and fourth editions ([16.46 +/- 3.08]% vs [15.22 +/- 3.51 ]% and [4.24 +/- 1.66]% vs [3.87 +/- 1.68]%, P > 0.05).

CONCLUSIONThe criteria of sperm morphology evaluation in the fifth edition of WHO Laboratory Manual are less strict than those in the fourth, and the percentage of morphologically normal sperm is higher according to the fifth edition.

Humans ; Male ; Semen Analysis ; standards ; Sperm Head ; ultrastructure ; Sperm Midpiece ; ultrastructure ; Sperm Motility ; Spermatozoa ; ultrastructure ; World Health Organization

AIMTo investigate the changes of the spermatozoa ultrastructures before and after renal transplantation in uremic patients.

METHODSThe sperm of five uremic patients before and after transplantation and four healthy volunteers were collected and examined by scanning electron microscopy.

RESULTSAbnormal spermatozoa were found in patients pre-transplantation; abnormalities included deletion of the acrosome, absence of the postacrosomal and postnuclear ring, dumbbell-like changes of the head, tail curling, and absence of the mitochondrial sheath in the mid-segment. After renal transplantation, most of the spermatozoa became normal.

CONCLUSIONThere are many abnormalities with regard to the appearance and structure of the head, acrosome, mitochondria and tail of the spermatozoa in uremic patients. The majority of the spermatozoa returned to normal after renal transplantation, but a few still presented some abnormalities possibly relating to the administration of immunosuppressants.

Acrosome ; pathology ; Adult ; Case-Control Studies ; Humans ; Kidney Failure, Chronic ; complications ; Kidney Transplantation ; Male ; Microscopy, Electron ; Renal Dialysis ; Sperm Head ; pathology ; Sperm Tail ; pathology ; Spermatozoa ; pathology ; ultrastructure

OBJECTIVE: Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test. METHODS: In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups. RESULTS: There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability. CONCLUSION: Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.
Acrosome ; Chromatin ; Cryopreservation ; DNA Fragmentation ; DNA ; Freezing ; Humans ; Infertility, Male ; Male ; Membranes ; Reproductive Techniques, Assisted ; Semen ; Semen Analysis ; Sperm Head ; Sperm Motility ; Spermatozoa ; Tail

Human sperm are not only pleomorphic but also tend to show large numbers of obvious abnormalities that may be associated with infertility. It is known that the greater the numbers of abnormalities present in each sperm (teratozoospermic index) relates closely to abnormalities in sperm function and the presence of infertility. The variation in morphology that may be seen among human sperm involve the head, midpiece and tail. An oval head is deemed to be normal but many shape and size variations can be seen in an ejaculate, and these include large, small or tapering heads. Amorphous heads are now known to be associated with chromosomal anomalies and a sperm may even show the presence of a double head. Another anomaly of sperm morphology that is occasionally seen is the abnormality known as globozoospermia. In this condition, the sperm head lacks an acrosome and, as a consequence, the head of each spermatozoon becomes rounded. We have experienced a case of globozoospermia which was conceived by intracytoplasmic sperm injection. So we report this case with a brief review of literatures.
Acrosome ; Head ; Humans ; Infertility ; Male ; Sperm Head ; Sperm Injections, Intracytoplasmic* ; Spermatozoa

SUMMARY: To investigate the influences on semen parameters and fertilizing capacity of immuno- globulin(Ig) isotypes and regional distribution of antisperm antibody (ASA) on the human sperm surface. Sixty-seven ASA-positive patients were compared with 96 ASA-negative donors. ASAs in semen showed significant negative effects on both semen parameters and fertilizing capacity; in those with ASAs in the sperm head and/or tail, the reductions were significant. In the head as well as the tail, there was close correlation between fertilizing capacity and both IgG and IgA. Both semen parameters and fertilizing capacity are significantly affected by the presence of ASA in semen. In particular, antibodies IgG to sperm head and/or tail, and antibodies IgA to sperm tail appeared to have a highly detrimental effect on fertilizing capacity.
Antibodies* ; Head ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Semen* ; Sperm Head ; Sperm Tail ; Spermatozoa ; Tissue Donors

AIMTo characterize mouse capping protein alpha3 (CPalpha3) during spermatogenesis and sperm maturation.

METHODSWe produced rat anti-CPalpha3 antiserum and examined the expression of CPalpha3 in various mouse tissues using Western blot analysis and the localization of CPalpha3 in testicular and epididymal sperm using immunohistochemical analyses. We also examined how the localization of CPalpha3 and beta-actin (ACTB) in sperm changed after the acrosomal reaction by performing immunohistochemical analyses using anti-CPalpha3 antiserum and anti-actin antibody.

RESULTSWestern blot analysis using specific antiserum revealed that CPalpha3 was expressed specifically in testes. Interestingly, the molecular weight of CPalpha3 changed during sperm maturation in the epididymis. Furthermore, the subcellular localization of CPalpha3 in sperm changed dynamically from the flagellum to the post-acrosomal region of the head during epididymal maturation. The distribution of ACTB was in the post-acrosomal region of the head and the flagellum. After inducing the acrosomal reaction, the CPalpha3 and ACTB localization was virtually identical to the localization before the acrosomal reaction.

CONCLUSIONCPalpha3 might play an important role in sperm morphogenesis and/or sperm function.

Acrosome Reaction ; physiology ; Actins ; metabolism ; Animals ; Blotting, Western ; CapZ Actin Capping Protein ; metabolism ; Cells, Cultured ; Epididymis ; cytology ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Sperm Head ; metabolism ; Sperm Tail ; metabolism ; Spermatogenesis ; physiology ; Spermatozoa ; cytology ; metabolism ; Testis ; cytology ; metabolism

Globozoospermia is a severe teratozoospermia, and the cases with 100% round-headed sperm are rare clinically. Globozoospermia is generally characterized by absence or abnormality of acrosome, accompanied by round-headed sperm with deranged midpiece and tails. The acrosome normally contains the enzymes that enable sperm to fertilize oocytes, while defective sperm cannot independently fertilize oocytes either in vivo or in vitro, and therefore globozoospermia makes males infertile clinically. Recent studies show that the deletion of the DPY19L2 (dpy-19-like 2) gene is a major cause of globozoospermia. This paper updates the relationship between DPY19L2 and globozoospermia to provide some evidence for further studies on the gene diagnosis and molecular mechanisms of globozoospermia.
Acrosome ; Humans ; Infertility, Male ; genetics ; Male ; Membrane Proteins ; genetics ; Sequence Homology ; Sperm Head ; Spermatozoa ; abnormalities

Successful male germ cell transplantation requires depletion of the host germ cells to allow efficient colonization of the donor spermatogonial stem cells. Although a sterilizing drug, busulfan, is commonly used for the preparation of recipient models before transplantation, the optimal dose of this drug has not yet been defined in dogs. In this study, 1-year-old mongrel dogs were intravenously injected with three different concentrations of busulfan (10, 15, or 17.5 mg/kg). Four weeks after busulfan treatment, no fully matured spermatozoa were detected in any of the busulfan-treated groups. However, small numbers of PGP9.5-positive spermatogonia were detected in all treatment groups, although no synaptonemal complex protein-3-positive spermatocytes were detected. Of note, acrosin-positive spermatids were not detected in the dogs treated with 15 or 17.5 mg/kg busulfan, but were detected in the other group. Eight weeks after busulfan treatment, the dogs treated with 10 mg/kg busulfan fully recovered, but those in the other groups did not. PGP9.5-positive spermatogonia were detected in the 10 mg/kg group, and at a similar level as in the control group, but these cells were rarely detected in the 15 and 17.5 mg/kg groups. These results suggest that a dose of 15-17.5 mg/kg is optimal for ablative treatment with busulfan to prepare the recipient dogs for male germ cell transplantation. At least eight weeks should be allowed for recovery. The results of this study might facilitate the production of recipient dogs for male germ cell transplantation and can also contribute to studies on chemotherapy.
Animals ; Busulfan* ; Colon ; Dogs* ; Drug Therapy ; Germ Cells ; Humans ; Male ; Spermatids ; Spermatocytes ; Spermatogonia ; Spermatozoa ; Stem Cell Transplantation* ; Stem Cells* ; Synaptonemal Complex ; Testis* ; Tissue Donors